1. Field of the Invention
The invention relates to an image processing method and an image processing apparatus for removing noise in an image.
2. Description of the Related Art
Examples of conventional techniques of removing noise include a method of removing noise with respect to each subband on a transform plane using a multi-resolution image separating technique, and a method of removing noise by dividing an image into blocks and gathering similar blocks. However, unlike noise in an actual image, conventional techniques assume independent Gaussian noise. Since noise in a captured image is signal dependent noise, it is difficult to remove using conventional techniques. Block matching in three dimension (BM3D) and video block matching in three dimension (VBM3D) methods from among conventional techniques remove noise in an image in 2 stages, but a second stage has high computational requirements and is difficult to realize in hardware. Also, while noise in a luminance channel may be well removed from an image, the noise in the luminance channel has to be repeatedly calculated in the second stage. In addition, a noise brush method is a post process method that can be used only on an image from which noise is primarily removed, and thus a user has to manually designate an area to apply the noise brush method.